As you know this came up before, so I will repost the the only contribution that I can on this topic so that any new readers can review the information. I have not seen this pattern enough to form an educated opinion myself.

In Andrew Mowbray's The American Eagle-Pommel Sword 1988 on Pg 58;

"Figure 1.A
Naval Officers' Sword ca. 1795 (Francis Thurkle)

One of the more commonly encountered Thurkle hiltings featuring a counter guard containing a pierced diamond see detail." (attached below)